How do I put a stencil-like texture across a sectioned object?
This can be done quite easily actually in the Cycles render engine with an empty and by using Object texture coordinates.

First create an empty and position it where you would like the decal to be placed on your object.



Now setup the following material nodes for the bars.



Make sure Min and Max are checked on the Mapping node, this clamps the edges of the texture so that it doesn't repeat infinitely.

Instead of the two diffuse shaders you can use whatever materials you would like for the plain bars and the stenciled text.  The bottom diffuse shader is for the text, the top diffuse shader is for the bars.

This leaves one problem however: since the texture is infinitely thick along the Z-axis the texture will be stretched across the inside edges of the bars undesirably.  To fix this amend the above node setup with some math nodes as follows.



The added nodes use a Less Than Math node to to test if the absolute value of the Z component of the mapping coordinates is within a certain range (in this case I am using threshold of 0.03).  The multiply node works like a logical AND between this test and the alpha channel of the decal texture.